Table 1.
Effect of SKF-38393, dopamine, 8-bromo-cAMP, and Rp-5,6-DCl-cBIMPS on spike frequencies and latencies
| Cell number | Ligand | [Ca2+]o | Spike frequency (Hz) | Latency to first spike (msec) | ||||
|---|---|---|---|---|---|---|---|---|
| Control | Test 1 | Test 2 | Control | Test 1 | Test 2 | |||
| 313074 | SKF | 2.5 | 40 | 32.7 | 31.0 | 40.9 | ||
| 315019 | SKF | 2.5 | 30 | 19.8 | 75.8 | 89.6 | ||
| 315035 | SKF | 2.5 | 40 | 32.4 | 35.4 | 43.4 | ||
| 316022 | SKF | 2.5 | 40 | 37.2 | 39.0 | 55.4 | ||
| 321028 | SKF | 0.1 | 30 | 13.3 | 24.9 | 54.1 | ||
| 329008 | DA | 0.2 | 60 | 49.9 | 15.5 | 20.5 | ||
| 118018 | SKF | 0.1 | 60 | 35.7 | 43.5 | 74.0 | ||
| 404012 | 8-br-cAMP | 0.2 | 40 | 31.1 | 58.4 | 83.9 | ||
| 416035 | 8-br-cAMP | 0.2 | 40 | 28.2 | 14.8 | 21.0 | ||
| 410016 | 8-br-cAMP | 2.5 | 40 | 34.0 | 28.5 | 31.4 | ||
| 414101 | 8-br-cAMP | 2.5 | 40 | 34.9 | 49.3 | 61.5 | ||
| cBIMPS | cBIMPS | |||||||
| 212017 | SKF | 2.5 | 40 | 30.7 | 35.4 | 32.8 | 38.9 | 33.7 |
| 219071 | SKF | 2.5 | 40 | 35.8 | 38.8 | 34.3 | 41.8 | 34.3 |
| 209165 | SKF | 2.5 | 40 | 30.5 | 35.0 | 20.1 | 28.2 | 20.3 |
Each row describes the spikes recorded in perforated-patch whole-cell mode from a single isolated retinal ganglion cell (n = 14). The test solutions contained SKF-38393 (SKF; 1–30 μm), dopamine (DA; 0.3–3 μm), 8-bromo-cAMP (8-br-cAMP; 100 μm), or Rp-5,6-DCl-cBIMPS (cBIMPS; 100–150 μm, applied together with SKF-39393). The external Ca2+ concentrations ([Ca2+]o) used in each recording are listed in millimoles per liter and were identical in all solutions applied to a given cell. Control and test spike frequencies are the ordinate values of the points at which a vertical line intersected linear regressions on plots, against stimulus current intensity, of the inverse of time elapsed between the first two spikes elicited by each current injection, in the solutions indicated. The latency to first spike is the time elapsed from the beginning of a current injection to the peak of the first spike elicited, in all of the solutions indicated, by the smallest amount of current that elicited spikes in the test solution. Latency values are means of measurements obtained from two to seven identical current injections into each cell in each solution.